Plank texture in mesh
Instead of cutting each plank (which you can do, depending on the level of realism that you want to give to your object) you could use your image to create a bump map, so that it creates a bit of 3D feeling:

Seam your object:



Unwrap:



Create a height map from your current wood plank picture, with a soft like Crazy Bump or with a site like this one :



Create this kind of node setup, plug the Bump node into the Normal input socket of the Principled BSDF:



Here is what it gives:



Once you've done that you can still create additional edge loops and move the planks the way you want, or even extrude, cut holes, etc: